In built-in electrical appliances, and in refrigerators in particular, when the front panel of the piece of furniture into which the refrigerator is built is opened (or closed) it is desirable that the refrigerator door should open (or close) at the same time, In order to resolve this problem it has been suggested that the two opposing sides of the panel and the refrigerator door should be connected by means of a slider and a guide which act together in such a way that when the panel is opened it causes the refrigerator door also to rotate, the panel and the door being hinged to the piece of furniture and the body of the refrigerator respectively in the normal way.
In this arrangement the connecting members between the panel and the door have to be adjusted frequently in order that the refrigerator door should shut properly. This adjustment is however quite difficult, and therefore it frequently happens that either the refrigerator door does not close properly or the panel is not flush with the other surfaces of the kitchen furniture when it is closed. Also, empty spaces have to be left both between the piece of furniture and the body of the refrigerator and between the panel and the refrigerator door in order to allow both the door and the panel to rotate simultaneously,
In order to overcome these disadvantages it has been suggested that the panel and the refrigerator door should be rigidly connected.
This arrangement too has given rise to problems. In fact the panel has to project by a certain amount with respect to the refrigerator door so as to at least partly cover the visible edges of the sides of the item of furniture into which the refrigerator is built. This hinders opening of the refrigerator door, as the edges of the panel and the side, by coming into contact, prevent the door from being opened if it is hinged using a hinge of a conventional type.
In order to overcome this problem different special types of hinge, e.g. the type produced by Hettict and mounted on refrigerators manufactured by the largest manufacturers of domestic appliances (e.g. Baucknecht, Electrolux, Zanussi) have been constructed. Such hinges comprise two supporting members which are linked respectively to the body and the door of the refrigerator and are attached together and to the supporting members by means of four bars so as substantially to provide two quadrilaterals which are hinged on two sides and have a common hinge point.
When the door opens the aforesaid hinge first brings about limited rotation of the door with respect to the front of the refrigerator so that the panel moves away from the edge of the item of furniture into which the refrigerator is built, and then permits greater rotation of the door itself so that the door can open through ninety or more degrees.
The Hettict hinge is however difficult and complicated to manufacture. For example seven pins are required to connect together the individual parts, and this has an appreciable effect on the times and costs involved in production of the hinge. Also, because of play in the pine due to tolerance or resulting from wear or yielding under load, the hinge does not ensure optimum door closure.
A type of hinge in which the two supporting members are connected in the manner of a hinged quadrilateral with only two pins and a return spring is also known, and is described in e.g. patent DE-A-2706821. This type of hinge is generally small, unsuitable for refrigerator doors and is only used for furniture door panels.